Where the urn is placed
Columbarium — special wall at crematorium or cemetery, with individual niches. Niche costs 3,000-8,000 RON, urn is inserted with externally-inscribed plaque. Concession is 7-15 years. Full details on cemetery concessions and columbarium.
Grave (burial plot) — urn is buried in existing or new plot, similar to traditional burial but with shallower depth. Concession cost is similar (10,000-30,000 RON for a new plot).
Home — Government Decision (HG) 741/2016 (Art. 40) regulates depositing the urn at the crematorium/cemetery or burial; keeping the urn at home isn't prohibited by law, but it also isn't mentioned separately as a regulated option. After cremation, the crematorium hands the urn to the family, and many families choose to keep it at home, in a suitable place (shelf, cabinet, personal altar).
Scattering in nature — there is no dedicated national rule on scattering ashes. If you're considering this option, check local rules and get consent from whoever owns the land or water in question, especially on private property.